For centuries, patients with limb amputations have required a prosthetic socket to cover their residuum as a means for attaching the prosthesis to their body. This traditional method constitutes indirect attachment, as an area of soft tissues and skin lies between the prosthesis and the residual bone. In order to eliminate or avoid pain and discomfort associated with indirect attachment, a technology of direct prosthetic attachment called "osseointegration" was introduced in the nineties (Eriksson and Branemark 1994). Despite the relatively successful integration of a titanium implant with the residual bone, the problem of the device-skin interface in the area where the implant goes outside of the residuum remains unsolved. The high risk of infection and secondary trauma precludes the technology of direct skeletal attachment from wide clinical studies and implementation. The proposed study is aimed at developing a new "Residuum-Integration Prosthetic Technology" to be used in limb prosthetics. The technology will include a "Skin and Bone Integrated Pylon" (SBIP), which will connect the residuum with external limb prosthesis. The SBIP will be integrated not only with the residual bone, but also with the residuum's skin in order to minimize the risk of infection and secondary trauma. The investigators will develop an optimal porous titanium matrix and design of the Skin and Bone Integrated Pylon, and also a biological process to maximize the ingrowth of bone and skin cells of the residuum to the SBIP. The mathematical modeling and mechanical testing will be followed by a technological study on the process of manufacturing of the composite porous structure enforced with a permeable internal frame. Inadequate prosthetic rehabilitation after limb amputation is a serious problem relevant to public health. The public value of solving this serious problem is much more elevated when a country is at war. Providing US Veterans with infection-safe direct skeletal attachment of prostheses will improve the quality of their lives and eliminate the costs associated with the multiple fabrications and adjustments of the prosthetic sockets. [unreadable] [unreadable] [unreadable] [unreadable]